81976415 has 8 divisors (see below), whose sum is σ = 99242928. Its totient is φ = 65000320.

The previous prime is 81976379. The next prime is 81976441. The reversal of 81976415 is 51467918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-81976415 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71981 + ... + 73110.

It is an arithmetic number, because the mean of its divisors is an integer number (12405366).

Almost surely, 2^81976415 is an apocalyptic number.

81976415 is a deficient number, since it is larger than the sum of its proper divisors (17266513).

81976415 is a wasteful number, since it uses less digits than its factorization.

81976415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145209.

The product of its digits is 60480, while the sum is 41.

The square root of 81976415 is about 9054.0827807128. The cubic root of 81976415 is about 434.4064923081.

The spelling of 81976415 in words is "eighty-one million, nine hundred seventy-six thousand, four hundred fifteen".